Website analytics is the measurement, collection, analysis and reporting of data relating to the usage of a website by various visitors. This information provides insight into visitor interactions and can be useful for optimizing website performance. Some existing website analytics techniques track anonymous and unidentified visitors based on cookies, device identification numbers or other data provided by a web browser. For instance, if a particular person visits a website multiple times using the same browser, each of those visits can be associated with the same person using cookies stored by the browser. This is one form of so-called visitor stitching, a process by which several distinct visits to a website by the same person are combined or otherwise associated with one another for analytical purposes. The analytics about a given person can then be converted into actionable intelligence, for example, in the context of a marketing strategy. For instance, if a given person frequently visits a website that sells a particular product, that person may be put on a mailing list to receive a copy of a catalogue from a company that sells that product.